JPH098361A - Light emitting diode - Google Patents

Abstract

PURPOSE: To obtain a light emitting diode in which purification (deodorization), pasteurization, prevention against contamination, purification of water, etc., can be carried out through photocatalysis. CONSTITUTION: The light emitting diode comprises one or more LED chips 2 comprising a photosemiconductor crystal having pn junction principally emitting ultraviolet rays having wavelength in the range of 360-400nm, a lens 3 molded of transparent synthetic resin sealing the LED chip 2, a cap 6 made of transparent glass being applied integrally to the outer surface of mold lens 3, and thin photocatalyst 7 of titanium oxide carried on the surface of the cap 6. The photocatalyst 7 is activated by ultraviolet rays emitted from the LED chip 2 to form an active surface exhibiting oxidizing power thus decomposing an organic compound. The light emitted from the LED chip 2 may contain visible light. The mold lens 3 may be eliminated to obtain a stem type LED.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode, and in particular, it carries a photocatalyst consisting of a thin film of titanium dioxide, and its photocatalytic reaction causes deodorization, sterilization, and stain resistance
The present invention relates to a light emitting diode capable of purifying water.

[0002]

2. Description of the Related Art Conventionally, as a pilot lamp or various indicators, or display of characters or figures, signals,
Light emitting diodes (LEDs), which are small semiconductor light emitting devices, are widely used for decoration, design, and the like.

This light emitting diode (LED) has a lead frame type, a stem type, or the like in terms of structure, and has a special shape such as a planar light emitting type for surface mounting, but either type. In the case of a shape, an LED chip basically made of a pn-junction optical semiconductor crystal and a molded lens generally made of an epoxy resin for sealing the LED chip and giving directivity to the emitted light. Is formed from (and
This molded lens is formed, for example, in a simple flat plate shape and may not give directivity to the emitted light, but in the present specification, it is made of a transparent material that seals the LED chip and guides the emitted light to the outside. The encapsulant is generally called "molded lens"). Further, this light emitting diode can emit various lights such as red, green, and blue depending on the kind of the crystal body of the optical semiconductor used and proper doping thereof. Further, a light emitting diode that emits ultraviolet light together with ultraviolet light or colored visible light is also known.

By the way, in recent years, a photocatalytic action by fine particles of an optical semiconductor represented by titanium dioxide TiO ₂ , particularly,
Attention has been focused on its strong oxidation catalytic action.

This photocatalytic action is generally considered as follows. That is, the particulate matter having optical semiconductivity such as titanium dioxide is irradiated with light having a band-cap energy higher than that (in the case of titanium dioxide, light having a wavelength of 400 nm or less, that is, ultraviolet rays).
When irradiated with, the electrons in the valence band are photoexcited and move to the conduction band, free electrons are generated in the conduction band, and positively charged particles (holes) are generated in the valence band. These holes and electrons move inside the semiconductor particles and recombine with the passage of time to disappear. However, outside the particles, there are vacant ranks lower in energy than air or water or those holes and electrons. In the presence of the compound or ion contained therein, those holes and electrons move through the surface of the particle. That is,
The holes that have moved to the surface of the semiconductor particles directly oxidize the contacting compound or ion or generate a hydroxyl radical which is one of active oxygen. Further, the reduction reaction by electrons with respect to this oxidation reaction is mainly reduction of oxygen, and oxygen species with high oxidizability to which electrons are added are generated. Thus, the photo-semiconductor fine particles form an oxidative active surface when irradiated with light, and act as a catalyst for decomposition of organic compounds (see "Quarterly Chemistry Review" Catalyst Chemistry Related to Light "No. 2).
3, 1994).

Among the optical semiconductors, titanium dioxide is particularly high in the oxidation catalytic action of such optical semiconductor fine particles. Titanium dioxide is also excellent in stability and safety. Therefore, various applications have already been known in which the fine powder of titanium dioxide is carried as a thin film on the surface of a substrate to form a photocatalyst, and the high oxidizing power at the time of ultraviolet irradiation is utilized for decomposing an organic compound or the like.

The best known example of its application is the cracking of crude oil spilled at sea. The photocatalyst consisting of the above-mentioned titanium dioxide thin film is supported on the surface of the hollow glass beads by coating. Then, the glass beads are scattered on the sea where crude oil has flown out. As a result, crude oil adheres to the surface of the glass beads, and this adhered crude oil has its photocatalyst activated by the ultraviolet rays in the sunlight,
It is decomposed by exerting a strong oxidation catalytic action. This was actually done by putting water into a petri dish on a trial basis, but it has been reported that crude oil can be completely decomposed in two weeks or one month under sunlight.

In recent years, its application has been attempted for deodorizing or deodorizing indoor air, sterilizing (antibacterial), and decomposing dirt such as tobacco tar and oil film. Specifically, these examples are those in which a photocatalyst consisting of a thin film of titanium dioxide is formed on the surface of a window glass, a glass tube of a fluorescent lamp, or a tile, and the ultraviolet rays contained in the natural light or the light of the fluorescent lamp are used. Then, the photocatalyst is activated to decompose the odorous compound such as mercaptan or the organic matter such as tobacco tar that is contacted by its oxidation catalytic reaction, or to kill or suppress the growth of microorganisms such as bacteria. is there. The actual effect of this has been confirmed, and window glass for automobiles, high-rise buildings, etc., or sanitary tiles are already in the stage of practical application.

Further, as an example which has been recently put into practical use, a photocatalyst comprising a thin film of titanium dioxide formed on the surface of a glass container such as a cup is known. According to this, since the photocatalyst is activated by the weak ultraviolet rays contained in the light of the fluorescent lamp, the chlorine odor contained in tap water is removed, and the organic halogen compound, especially trihalomethane of carcinogenic substance is removed. Can be disassembled. In addition, the photocatalyst also has the effect of making water clusters (aggregates of molecules) finer, and has the effect of producing delicious water.

Although other application examples have not been put to practical use, purification of wastewater such as industrial wastewater, detoxification or decomposition of air pollutants such as nitrogen oxides, and further cancer cell treatment as a medical application. Elimination and removal. In these examples of wastewater treatment, a photocatalyst consisting of a thin film of titanium dioxide is supported on a substrate having a large surface area such as a honeycomb or ceramics wool, and the light source is strong sunlight or strong ultraviolet fluorescent lamp (black light). Is used.

It is known that in a photocatalyst composed of a thin film of titanium dioxide, the smaller the particle size of titanium dioxide forming the thin film, the higher the photocatalytic action due to the "quantum size effect" or the like. Therefore, the thin film is formed as a transparent thin film having a thickness of generally 0.3 μm or less, preferably 0.2 μm or less by a method such as coating a titanium dioxide colloid on the surface of the substrate and baking, or forming such a thin film. It is formed as a multi-layered thin film.

[0012]

As described above, the photocatalyst composed of a thin film of titanium dioxide (TiO ₂ ) produces a high oxidation catalytic action by being irradiated with ultraviolet rays and can decompose organic compounds and the like. . Therefore, by supporting this photocatalyst on a suitable substrate surface, as described above, it is effectively used for deodorizing or deodorizing air, sterilization (antibacterial), antifouling of cigarette tar, or water purification. be able to.

However, the problem here is that ultraviolet rays are necessary for activating the photocatalyst consisting of the thin film of titanium dioxide and thereby causing a catalytic reaction such as decomposition of organic compounds. . As the ultraviolet ray source, conventionally, the ultraviolet ray contained in the natural light of the sun or the light of the fluorescent lamp has been mainly used. However,
The use of these lights has the advantage that no new light source is required, but the places where the catalytic reaction system using the photocatalyst is applied are naturally limited. That is, the photocatalyst cannot be applied to a place where the light is not radiated or is not sufficiently radiated, and the substrate supporting the photocatalyst is
It is limited to a window glass or a fluorescent lamp cover that can fully receive those lights, or a glass cup that can be placed under those lights. Further, it takes some time to completely decompose the organic compound and the like by the photocatalytic reaction of the photocatalyst, but the photocatalytic reaction cannot be caused at night or when the light is turned off.

Therefore, it is conceivable to use an ultraviolet fluorescent lamp (black light) as an ultraviolet ray source for causing a catalytic reaction by a photocatalyst, and actually, in the past, an ultraviolet fluorescent lamp is used especially for tests. Has been done. However, such an ultraviolet fluorescent lamp requires a relatively large space and a place to install it, and cannot be installed in a narrow space or the like. Also, its power consumption is quite high when used all day. Therefore, also in the case of the ultraviolet fluorescent lamp, the ultraviolet rays emitted by the ultraviolet fluorescent lamp include a lot of far ultraviolet rays which are harmful to the human body, and the specific application place thereof is limited.

Therefore, the present invention aims to provide a light-emitting diode which is capable of purifying (deodorizing) air, sterilizing (antibacterial), antifouling, purifying water and the like by the catalytic action of a photocatalyst and is expected to be widely used. It is what

[0016]

A light emitting diode according to claim 1 is composed of a pn-junction optical semiconductor crystal and mainly emits ultraviolet rays having a wavelength of 360 to 400 nm.
The above LED chip, a transparent lens that seals the LED chip, a cap made of a transparent glass material that is integrally coated on the outer surface of the lens, and a photocatalyst carried on the surface of the cap are provided. To do.

A light emitting diode according to a second aspect is a pn
It is composed of bonded optical semiconductor crystals and has a wavelength of 360 to 4
It is provided with one or more LED chips that mainly emit 00 nm ultraviolet light, a lens made of a transparent material that seals the LED chips, and a photocatalyst carried on the outer surface of the lens.

The light emitting diode according to claim 3 is a pn
It is composed of bonded optical semiconductor crystals and has a wavelength of 360 to 4
One or more LED chips that mainly radiate ultraviolet rays of 00 nm, a stem that supports the LED chips, a cap that is hermetically fixed to the stem and is made of a transparent material that seals the LED chips, and the outside of the cap. And a photocatalyst carried on the surface.

A light emitting diode according to a fourth aspect is the light emitting diode according to any one of the first to third aspects, wherein the photocatalyst is a thin film of titanium dioxide.

A light emitting diode according to claim 5 is the LED according to any one of claims 1 to 4.
The chip is a chip that mainly emits colored visible light and the ultraviolet light.

A light emitting diode according to claim 6 is the LED according to any one of claims 1 to 5.
The chip emits mainly blue light and the ultraviolet light pn
It is composed of a bonded gallium nitride (GaN) -based optical semiconductor crystal body.

[0022]

According to the present invention, the ultraviolet light emitted from the LED chip passes through the transparent lens and the cap made of a transparent glass material covering the transparent lens, and hits the photocatalyst carried on the surface thereof. , Activate this. Then, the activated photocatalyst forms an active surface having an oxidizing power as described above, and thus oxidatively decomposes an odor component or an organic compound such as tobacco tar that comes into contact with the active surface,
It also kills or inhibits the growth of microorganisms such as bacteria that come into contact with it. Therefore, it is possible to obtain a light emitting diode capable of performing air purification (deodorization), sterilization (antibacterial), antifouling of cigarette tar, and water purification by such a photocatalytic reaction. Furthermore, in the case of multiple LED chips, more ultraviolet rays are emitted,
Also, since more visible light with color is emitted,
The photocatalytic reaction ability of the photocatalyst can be further increased, and the emission capacity of colored visible light can be increased. Therefore, by the photocatalytic reaction of the photocatalyst, it is possible to purify air (deodorize), sterilize (antibacterial), prevent stains on the tar of the cigarette, purify water, and emit chromatic color. A highly efficient light emitting diode can be obtained.

In the second aspect, the ultraviolet rays emitted from the LED chip pass through the lens made of a transparent material,
It hits the photocatalyst carried on its surface and activates it. Therefore, as in the case of claim 1, to obtain a light emitting diode capable of performing air purification (deodorization), sterilization (antibacterial), antifouling of cigarette tar, and water purification by photocatalytic reaction of photocatalyst. You can Furthermore, in the case of a plurality of LED chips, more ultraviolet light is emitted, and more visible light having a color is also emitted, so that the photocatalytic ability of the photocatalyst is increased, and
The emission capacity of colored visible light can be increased. Therefore, by the photocatalytic reaction of the photocatalyst, it is possible to purify air (deodorize), sterilize (antibacterial), prevent stains on the tar of the cigarette, purify water, and emit chromatic color. A highly efficient light emitting diode can be obtained.

In the third aspect, the ultraviolet light emitted from the LED chip passes through the cap made of a transparent material and hits the photocatalyst carried on the outer surface thereof to activate it. Therefore, as in the case of claim 1, to obtain a light emitting diode capable of performing air purification (deodorization), sterilization (antibacterial), antifouling of cigarette tar, and water purification by photocatalytic reaction of photocatalyst. You can Furthermore, LE
With a plurality of D chips, more ultraviolet rays are emitted, and more visible light having color is also emitted, so that the photocatalytic reaction ability of the photocatalyst is enhanced and the visible light having color is also produced. The light emission capacity can be increased. Therefore, by the photocatalytic reaction of the photocatalyst, it is possible to purify air (deodorize), sterilize (antibacterial), prevent stains on the tar of the cigarette, purify water, and emit chromatic color. A highly efficient light emitting diode can be obtained.

According to the present invention, the ultraviolet rays emitted from the LED chip hit the photocatalyst formed into a thin film of titanium dioxide and efficiently activate it.

In the fifth aspect, the visible light having a color of the emitted light emitted from the LED chip is not absorbed by the photocatalyst, and therefore passes through it as it is. Therefore, air purification (deodorization) by photocatalytic reaction of photocatalyst,
It is possible to perform sterilization (antibacterial), antifouling of tobacco tar, purification of water, and the like, and obtain a light emitting diode that emits light in that color.

In the sixth aspect, since the blue light is close to the wavelength of the ultraviolet light, the spectrum of the emitted light of the LED chip can be made relatively narrow, and higher luminous efficiency can be obtained. You can Therefore, the photocatalytic reaction of the photocatalyst can purify air (deodorize), sterilize (antibacterial), prevent stains on the tar of cigarettes, purify water, etc., and can also emit blue light, and the luminous efficiency is high. A good light emitting diode can be obtained.

[0028]

Embodiments of the present invention will be described below.

[First Embodiment] FIG. 1 is a sectional view schematically showing a light emitting diode according to a first embodiment of the present invention.

As shown in FIG. 1, the light emitting diode of the present embodiment, which is designated by 1 in its entirety, is an LED chip 2 that emits light (electromagnetic waves) made of a pn-junction semiconductor crystal body, and this L chip.
The mold lens 3 for sealing the ED chip 2 is provided. The molded lens 3 is made of a transparent synthetic resin material such as epoxy resin or acrylic resin,
Further, it is formed in a lens shape so as to give directivity to the emitted light from the LED chip 2 and guide it to the outside. Also,
The light emitting diode 1 of the present embodiment is formed in a lead frame shape, and L is attached to the tip of one external lead 4 which also serves as a frame.
The ED chip 2 is fused and the LED chip 2
The p-side electrode and the other external lead 4 are connected by a gold wire 5. This structure is the same as a general light emitting diode, and the structure of the light emitting diode including the LED chip 2 and the mold lens 3 may be a stem type including a ceramic stem.

In the light emitting diode 1 of this embodiment, a cap 6 made of a glass material is integrally provided so as to cover the outside of the molded lens 3, and titanium dioxide is further provided on almost the entire outer surface of the cap 6. The photocatalyst 7 composed of the thin film of is carried. Also here, LED
The chip 2 mainly emits ultraviolet rays (near ultraviolet rays) having a wavelength of 360 to 400 nm, that is, a sufficient capacity.

Therefore, when the light emitting diode 1 is operated by applying a forward voltage, the LED chip 2 emits light including the ultraviolet rays, the ultraviolet rays pass through the mold lens 3, and further pass through the cap 6, The photocatalyst 7 on the surface is irradiated. As a result, the photocatalyst 7 is activated, and a photocatalytic reaction such as decomposition of an organic compound is caused by its catalytic action, particularly an oxidation catalytic action. Then, for example, when it is brought into contact with air in a room or the like containing an organic compound such as a mercaptan or a tobacco odor component, or an organic solvent, these organic compounds are oxidatively decomposed, so that the air is purified, Can be deodorized.

The light emitting diode 1 (photocatalyst 7)
When contacted with water such as drinking water, it may decompose harmful compounds such as trihalomethane dissolved in it, and decompose caustic odors, causative substances of mold odor (for example, 2-methylisoborneol), etc. You can, and you can purify the water. In addition, the activated photocatalyst 7 also has a function of subdividing water clusters (aggregates of water molecules), whereby tasty and healthy water can be produced.

Furthermore, the oxidizing power of the activated photocatalyst 7 is
Bacteria, molds and other microorganisms that come into contact with this are killed or their growth is inhibited. Therefore, this light emitting diode 1 forms a germicidal and antibacterial surface, and provides a hygienic and clean surface.

As described above, the light emitting diode 1 of this embodiment
According to the above, to obtain a light-emitting diode as a photocatalytic reaction element capable of purifying air (deodorization), antibacterial (sterilization), preventing contamination by adhering tobacco tars and oil films (antifouling), and purifying water. You can And this light emitting diode 1
Since it is formed as a small element, it can be easily applied and installed in any place including a narrow place.

Here, the LED chip 2, the mold lens 3, the cap 6, and the photocatalyst 7 which basically form the light emitting diode 1 of this embodiment will be described in more detail.

<LED Chip> The LED chip 2 is pn
It consists of bonded semiconductor crystals. Then, such an LED chip emits light of various spectra depending on the type of the semiconductor crystal, but in the present embodiment, the wavelength of 360 to 400 n is required for activation of the photocatalyst 7.
Those that mainly emit m light (near ultraviolet rays) are used.
That is, titanium dioxide has a light absorption spectrum peak at 380 to 390 nm (theoretical value is 388 nm).
Therefore, the LED chip 2 has a wavelength of 360 to 400.
Those capable of sufficiently emitting ultraviolet light in the nm range are used.

In order to obtain the light emitting diode 1 which functions as a photocatalytic reaction element, the LED chip 2 is
It is preferable in terms of light emission efficiency and power consumption to emit only light in the spectral range of 360 to 400 nm. However, in practice, the light emitted by the light emitting diode generally has a spectral range of at least 50 nm, which is different from the case of a semiconductor laser, and thus it is difficult to obtain an LED chip that emits light having a wavelength of 360 to 400 nm. is there. Therefore, LE used here
The D chip 2 may be any one that radiates light (electromagnetic waves) sufficiently containing ultraviolet rays having a wavelength of 360 to 400 nm.

However, the LED chip 2 preferably does not emit ultraviolet rays harmful to the human body, that is, far ultraviolet rays having a wavelength of 320 nm or less. Furthermore,
More preferred is an LED chip that does not emit not only deep UV rays but also UV rays that cause sunburn (B-rank UV rays), that is, that does not substantially emit UV rays having a wavelength of 350 nm or less. With such an LED chip, it is possible to form the light emitting diode 1 which is completely harmless to the human body, and it can be safely used for applications in daily life. Therefore, it is preferable that the LED chip 2 to be used emit substantially only light having a wavelength of 350 nm or more (more preferably 360 nm or more) (provided that the emitted light of the LED chip 2 includes deep ultraviolet rays). If so, at least part of it can be absorbed by the photocatalyst 7.)

On the other hand, visible light having a wavelength of 400 nm or more passes through the photocatalyst 7 without being substantially absorbed, but since it is harmless to the human body, such visible light is used. An LED chip that emits light including can be used without any problems. Further, by using such an LED chip, it can be easily confirmed that the light emitting diode 1 is operating. Furthermore,
If the visible light is a bright color, the light emitting diode 1
Emits light in such a color, so that the light emitting diode 1 having the functions of illumination and display means can be obtained.

That is, it is one of the preferable embodiments that the LED chip 2 mainly emits visible light having color and ultraviolet rays having a wavelength of 360 to 400 nm. As a result, it is possible to obtain the light emitting diode 1 having a function as a visible light emitting lamp and capable of performing a photocatalytic reaction such as purification of air.

The visible light can be any chromatic color such as red, green, or blue, and the LED chip 2 that mainly emits such visible light and the above-mentioned ultraviolet rays.
Can be appropriately obtained by selecting the type of semiconductor crystal body that forms it and performing appropriate doping treatment or the like. However, blue light having a wavelength of about 450 nm is more preferable as the chromatic visible light. According to this, the spectral range of the light emitted by the LED chip 2 can be made relatively narrow, and higher luminous efficiency can be obtained. The LED chip 2 that mainly emits the blue light and the ultraviolet light having a wavelength of 360 to 400 nm is a gallium nitride (GaN) -based, silicon carbide (SiC) -based semiconductor crystal body that forms the LED chip 2.
Generally, it can be manufactured using a semiconductor material such as a system, a zinc sulfide (ZnS) system, a selenium sulfide (SeS) system.
However, among these semiconductor materials, a gallium nitride (GaN) -based semiconductor material makes it possible to obtain the LED chip 2 having the highest light emission efficiency.

The power supply for operating the LED chip 2 (light emitting diode 1) is the same as that for a general light emitting diode. In particular, since it can be operated at a low voltage and consumes less power, a storage battery such as a dry battery or a rechargeable battery can be used as appropriate. for that reason,
The light emitting diode 1 of this embodiment can be applied to a place where there is no power supply wiring, and can cause a photocatalytic reaction. It is also possible to use a household AC power supply. In this case, for example, half-wave rectification may be simply performed using a silicon diode, or two light emitting diodes 1 may be connected in opposite directions and used, so that the power source can be easily used. Further, the power supply circuit may be provided with a switch, a timer, etc., whereby unnecessary operation of the light emitting diode 1 can be eliminated and power consumption can be saved.

<Molded Lens> The molded lens 3 is
As described above, it is for sealing the LED chip 2 and for transmitting the emitted light emitted by the LED chip 2 to the outside. Therefore, the molded lens 3 is formed of a light-transmissive transparent material, and generally can be formed of a synthetic resin material such as epoxy resin, acrylic resin, or polycarbonate. This transparent synthetic resin material is used when the LED chip 2 emits colored visible light together with ultraviolet rays.
It can also be colored in that color.

The molded lens 3 is an LED
As long as the chip 2 can be sufficiently sealed, it can be formed in an appropriate shape. For example, in the case of FIG. 1, in order to give directivity to the emitted light from the LED chip 2, it is formed in the shape of a convex lens having a rounded tip. Further, in addition to the lens shape, for example, the tip can be formed to have a flat tip. In this case, by mixing a light dispersion material such as silica powder into the tip portion of the molded lens 3, dispersed (diffused) light emission can be achieved. Type light emitting diode 1
Can be obtained.

In a general light emitting diode, L
As a sealing body for sealing the ED chip, a metal cap having a glass lens at its tip is also known. Therefore,
Instead of the molded lens 3, such a metal cap can be used as a sealing body for the LED chip 2. In this case, the photocatalyst 7 is carried on the outer surface of the lens. However, since the molded lens 3 made of a transparent synthetic resin material can be easily molded by a casting molding method, a transfer molding method, or the like, there is an advantage that the manufacturing is easy.

<Cap> The cap 6 serves to support the photocatalyst 7 on its outer surface as a carrier to provide a photocatalytic reaction surface, and is integrally provided on the molded lens 3 so as to cover it. Therefore, this cap 6
Is formed of a transparent material so that the light emitted from the LED chip 2 together with the molded lens 3 can be transmitted. The transparent material forming the cap 6 may be any material that is inactive to the photocatalytic action of the photocatalyst 7, particularly the oxidation catalytic action, and a synthetic resin material such as polycarbonate or acrylic resin may also be used. You can However, since the synthetic resin material is deteriorated by the photocatalytic action of the photocatalyst 7 for a long time, it is not very preferable. Further, although glass ceramics is a chemically stable material, its molding is relatively difficult. Therefore, as the transparent material forming the cap 6, a glass material is preferable in terms of chemical stability and moldability. As the glass material, quartz glass, high silica glass, borosilicate glass, or the like is preferable in terms of strength and the like, but ordinary soda lime glass or the like can also be suitably used.

Although the cap 6 can be formed in an appropriate shape, it is generally formed in a shape according to the shape of the molded lens 3, that is, in a cover shape having a uniform thickness. However, since the cap 6 is formed integrally with the molded lens 3, for example, when forming the light emitting diode 1 having a convex lens shape, the tip portion of the cap 6 itself can be formed thick. Further, the outer surface of the cap 6 may be provided with irregularities, projections, or a rough surface in order to further increase the surface area capable of supporting the photocatalyst 7 and thereby enhance the photocatalytic reaction. Although such a rough surface can be formed by mechanical processing or the like, it can also be formed by fusing glass powder to the surface of the cap 6.

By the way, the light emitting diode 1 of this embodiment is formed as having a single LED chip 2, and therefore the cap 6 is formed in a shape like a pencil cap. It is also possible to form a similar light emitting diode 1 by arranging a plurality of
In that case, the cap 6 is formed in a shape corresponding thereto. This will be described in a later example.

<Photocatalyst> The photocatalyst 7 carried on the surface of the cap 6 is a thin film of titanium dioxide (TiO ₂ ) which is an optical semiconductor, specifically, a coating of fine particles thereof. As optical semiconductors that cause similar photocatalytic reactions, various ones such as zinc oxide (ZnO), cadmium sulfide (CdS), zinc sulfide (ZnS), and strontium titanate are known. Dissolves in water when exposed to light as zinc ions. On the other hand, titanium dioxide not only has high photocatalytic reactivity, but is chemically stable and persistent in reaction (permanent), and is completely harmless to the human body.

It is already known that the fine particles of titanium dioxide forming the photocatalyst 7 need to be sufficiently small due to the "quantum size effect" or the like in order to cause the photocatalytic reaction. Therefore, the titanium dioxide thin film is generally a transparent thin film having a thickness of 0.3 μm or less, preferably 0.2 μm or less, or a thin film in which such a thin film is multilayered (for example, about 0.7 μm to 1 μm). Transparent thin film). Note that such a thin film generally exhibits a pale iris.

Such a thin film of titanium dioxide can be formed by a cap 6 as a carrier by various known methods.
Can be formed on the surface of. The most common way is
It is a method in which a colloid (sol) of titanium dioxide is thinly applied to the surface or is deposited by an electrophoretic method and then baked. According to this method, a sufficiently small thin film of titanium dioxide fine particles can be obtained, and further, a thin film firmly adhered to the cap 6 made of a glass material can be formed. Further, the vacuum vapor deposition method or the chemical deposition method by vapor phase reaction (vapor phase growth method) is particularly suitable when the support is made of a plastic material. In addition, "pearl raster" which has been used for a long time for imparting a pearly luster to craft porcelain such as Buddhist altars can also be appropriately used. This is a solution of titanium resin soap, and a transparent thin film of titanium dioxide can be formed by applying this solution and heating and baking it at about 600 ° C.

The light emitting diode 1 of the present embodiment provided with the cap 6 carrying the photocatalyst 7 has, for example, the photocatalyst 7 previously carried on the outer surface of the cap 6, and then the cap 6 is molded together with the LED chip 2 into a mold. It can be easily manufactured by a method in which the molded lens 3 is placed inside and then the molded lens 3 is molded by a casting molding method or the like. Further, the light emitting diode 1 can be similarly obtained by a method in which the cap 6 carrying the photocatalyst 7 is covered with and bonded to the light emitting diode element in which the LED chip 2 is sealed with the mold lens 3 in advance using a transparent adhesive. Can be made.

As described above, the light emitting diode 1 of this embodiment
Is composed of a pn-junction optical semiconductor crystal and has a wavelength of 3
An LED chip 2 that mainly emits ultraviolet rays of 60 to 400 nm, a molded lens 3 made of a transparent synthetic resin material that seals the LED chip 2, and the molded lens 3
A cap 6 made of a transparent glass material and integrally coated on the outer surface of the above, and a photocatalyst 7 made of a thin film of titanium dioxide carried on the surface of the cap 6. Therefore, as described above, the light-emitting diode 1 capable of performing air purification (deodorization), sterilization (antibacterial), antifouling, water purification, etc. by the photocatalytic reaction of the photocatalyst 7.
(Photocatalytic reaction element) can be obtained.

The LED chip 2 has a wavelength of 3
It is also possible to use those which mainly emit visible light having a color together with ultraviolet rays of 60 to 400 nm. According to this, since the visible light is not absorbed by the photocatalyst 7, the light emitting diode 1 emits light in its color, so that the light emitting diode 1 capable of performing a photocatalytic reaction such as deodorization and having a function as a visible light emitting lamp can be obtained. Obtainable. In this case, since ultraviolet rays are absorbed by the photocatalyst 7,
There is also an effect that such harmful ultraviolet rays are removed in some cases. Therefore, such a light emitting diode 1 can be preferably used in applications such as display, lighting, and decoration.

For example, a plurality of the light emitting diodes 1 are connected to each other through a suitable socket or directly by an electric wire to form a light emitting lighting ornament for use in a Christmas tree. By using it as it is in the room or by attaching it to an appropriate upholstery substrate, it is possible to deodorize not only the interior decoration but also the odor of cigarettes.

Further, the light emitting diode 1 can be used as it is instead of a general visible light emitting diode used as a pilot lamp, an indicator, or a dot matrix display. In this case, although there is an effect that the air that comes into contact with it can be purified, it has an effect that the tar and plaque of the attached tobacco are decomposed and a clean light emitting surface is always maintained.

[Second Embodiment] FIG. 2 is a sectional view schematically showing a light emitting diode according to a second embodiment of the present invention. In addition,
In the figure, the same reference numerals are used for the same or corresponding parts as in the first embodiment of FIG.

As shown in FIG. 2, the light emitting diode of this embodiment, which is indicated by 10 in its entirety, can be seen from the comparison with FIG.
The cap 6 in the light emitting diode 1 of the first embodiment is omitted, and the photocatalyst 7 is directly carried on the surface of the molded lens 3. That is, the light emitting diode 10 of this embodiment
Is composed of a pn-junction optical semiconductor crystal and has a wavelength of 3
Photocatalyst consisting of an LED chip 2 that mainly emits ultraviolet rays of 60 to 400 nm, a molded lens 3 made of a transparent material that seals the LED chip 2, and a thin film of titanium dioxide carried on the surface of the molded lens 3. And 7 are provided.

The technical details of the LED chip 2, the mold lens 3 and the photocatalyst 7 are the same as those in the first embodiment. For example, the LED chip 2
Can mainly emit colored visible light and ultraviolet light having a wavelength of 360 to 400 nm. However,
In the case of the light emitting diode 10 of the present embodiment, the mold lens 3 can be formed of a synthetic resin material as in the case of the first embodiment, but if necessary, a chemically stable glass material ( However, it can also be formed from (having a low melting point).

The operation and effect of the light emitting diode 10 of this embodiment are the same as those of the first embodiment, and the photocatalyst 7
It is possible to obtain the light emitting diode 10 capable of purifying air and the like by the photocatalytic reaction. Since the photocatalyst 7 is directly carried on the surface of the molded lens 3, there is an effect that the photocatalyst 7 can be manufactured more easily and at lower cost than in the case of the first embodiment. However, since a high temperature cannot be applied when forming the photocatalyst 7, the forming method thereof is limited to the vacuum deposition method or the like.
Therefore, the light emitting diode 10 of the present embodiment has the photocatalyst 7
Since it is relatively easy to peel off, it is not suitable for applications in which strong adhesion is required.

[Third Embodiment] FIG. 3 is a sectional view schematically showing a light emitting diode according to a third embodiment of the present invention. In addition,
In the figure, the same reference numerals are used for the same or corresponding parts as in the first embodiment of FIG.

As shown in FIG. 3, in the light emitting diode of the present embodiment, which is generally designated by 20, the mold lens 3 in the light emitting diode 1 of FIG. 1 is omitted, and the cap 6 carrying the photocatalyst 7 is sealed for the LED chip 2. It is a stationary body.
Therefore, the light emitting diode 20 of the present embodiment is generally provided with the stem 8 as a base portion formed of a ceramic material, and the LED chip 2 is attached to the stem 8 together with the external lead 4 and fixedly supported. The cap 6 carrying the photocatalyst 7 is hermetically fixed to the stem 8 by adhesion, that is, via the adhesive layer 9. As the adhesive, an appropriate adhesive such as epoxy, silicon, or urethane is used.

Here, the technical details of the LED chip 2, the cap 6 and the photocatalyst 7 are the same as in the first embodiment. The cap 6 can be formed of a transparent material such as glass or a transparent resin material, and its shape is not limited to the hat-like shape shown in the drawing, but can be a hemispherical shape or a flat shape. Can be any shape. Further, this cap 6 can be formed in a shape such as a convex lens at the tip end portion thereof in order to give directivity to the light emitted from the LED chip 2. Alternatively, a rough surface or the like may be formed on the inner surface of the cap 6 in order to disperse or diffuse the emitted light.

In this way, the light emitting diode 2 of this embodiment is
No. 0 is made of a pn-junction optical semiconductor crystal body having a hollow internal stem shape, and has a wavelength of 360 to 400 nm.
LED chip 2 that mainly emits the ultraviolet rays of
It consists of a stem 8 for fixing and supporting the chip 2, a cap 6 made of a transparent material for adhesively fixing to the stem 8 and sealing the LED chip 2, and a thin film of titanium dioxide carried on the outer surface of the cap 6. The photocatalyst 7 is provided.

The action and effect are that the LED chip 2 has a visible light having a color and a wavelength of 360 to 400 nm.
Including the case of using the one that mainly emits the ultraviolet rays of
As in the case of the first embodiment, it is possible to obtain the light emitting diode 20 capable of performing air purification (deodorization) and the like by the photocatalytic reaction of the photocatalyst 7. Therefore also
The light emitting diode 20 of this embodiment can be used for the same purpose as the light emitting diode 1 of the first embodiment. In addition,
The light emitting diode 20 of this embodiment takes a relatively long time to manufacture, but since it has the stem 8 as the base, it is LE.
The D chip 2 can be accurately positioned and arranged.

[Fourth Embodiment] The light emitting diodes 1, 10 and 20 of the above embodiments are provided with a single LED chip 2 and are formed as a minimum unit of light emitting diodes. And these light emitting diodes 1, 1
0 and 20 can be used by collecting them in a bundle, for example, in the required number depending on the required photocatalytic reaction capacity or the capacity of the emitted visible light (colored light). However, it is also possible to integrate these in advance to form a single light emitting diode having a plurality of LED chips 2.

FIG. 4 is a plan view showing a light emitting diode of a fourth embodiment of the present invention. 5 is a sectional view taken along the line AA of FIG. 1 to 3 in these figures.
The same reference numerals are used for parts that are the same as or correspond to those in the first to third embodiments.

As shown in FIGS. 4 and 5, the light emitting diode of the present embodiment, which is designated by 30 in its entirety, has a plurality of LED chips 2 (4 in this embodiment) in the hollow stem type light emitting diode 20 of FIG. This is intended to increase the ability of photocatalytic reaction such as deodorization and the capacity of radiated visible light.

Specifically, the light emitting diode 3 of this embodiment is
0 is equipped with a stem 8 forming a plate-shaped base.
In addition, a plurality (four) of LED chips 2 are fixedly attached together with the external leads 4 and supported in a linear array. In addition, the cap 6 that holds the photocatalyst 7 on the outer surface
LED chips 2 made of a transparent material such as glass.
It is formed in a cover shape (dish shape) that covers the above, and is formed in a shape having a rectangular flat outer surface. And
The cap 6 is hermetically adhered to the stem 8 via an adhesive layer 9. The LED chip 2 is provided on at least one of the outer surface and the inner surface of the cap 6.
A rough surface is formed to disperse or diffuse visible light from the. Furthermore, the photocatalyst 7 is formed in advance before the cap 6 is bonded to the stem 8 and is carried on almost the entire outer surface thereof.

The light emitting diode 30 of this embodiment is formed in this way, and basically the same as in the third embodiment of FIG.
It is composed of an n-junction optical semiconductor crystal and has a wavelength of 360 to
A plurality of LED chips 2 that mainly emit 400-nm ultraviolet light and a stem 8 that fixedly supports these LED chips 2.
And a cap 6 made of a transparent material, which is adhesively fixed to the stem 8 and seals the LED chips 2, and a photocatalyst 7 made of a thin film of titanium dioxide carried on the outer surface of the cap 6. It is a thing. Here, these LED chips 2 can emit visible light having a color together with the ultraviolet rays thereof, as in the above-described embodiments.

Therefore, the light emitting diode 3 of this embodiment is
The action and effect of 0 is the same as before, and air purification (deodorization), sterilization (antibacterial), antifouling, water purification and the like can be performed by the photocatalytic reaction of the photocatalyst 7. In addition, when the LED chip 2 that emits light including visible light having color in addition to ultraviolet rays is used, the light emitting diode 30
Emits light in that color, so that it is possible to obtain the light emitting diode 30 that also serves as display, lighting, decoration, or the like.

The light emitting diode having a plurality of LED chips 2 as described above can be formed in the same manner even if it is of the all-mold type as in the first embodiment of FIG. 1 and the second embodiment of FIG. it can. That is, in these cases, the stem 8 in the light emitting diode 30 of this embodiment is the molded lens 3
Instead, the molded lens 3 is filled in the entire space inside the cap 6. Further, the stem 8 is provided as it is, and in the space between the stem 8 and the cap 6,
Further, the molded lens 3 can be formed by filling a transparent synthetic resin material. Which of these forms can be determined depending on the specific application and the like.

In the light emitting diode 30 including a plurality of LED chips 2 as described above, including the case where the LED chips 2 are formed in the entire mold shape, the number of the LED chips 2 and the total size thereof are required to be deodorized. It can be appropriately determined depending on the photocatalytic reaction ability such as the above and the emission capacity of visible light. Therefore, such a light emitting diode 30 is
The deodorizing device can be applied not only in a narrow space such as a refrigerator but also in a relatively wide space such as a toilet or a changing room (or as a deodorizing device that also serves as a lighting device).

As for the overall shape, not only the relatively flat shape having the flat surface as in this embodiment,
It can be formed into any other shape such as a curved surface, a spherical shape or a hemispherical shape, or a ring shape. However, since a relatively flat shape such as the light emitting diode 30 of this embodiment does not project, it is suitable for installation on the inner wall surface of a refrigerator, a tableware dryer, a clothes dryer, or the like, or the wall surface of a general building. It is suitable. Therefore, such a light emitting diode 30 can also be applied as a wall surface display device for displaying guidance and the like. Further, such a flat surface of the light emitting diode 30 can be used as, for example, a portion on which the foot of the scale is put, that is, a tread portion. In this case, the tread surface can be always kept hygienic by the sterilizing (antibacterial) power of the photocatalyst 7. When applied to the inner wall surface of a drinking water container such as a pot, it can be formed into a curved surface or a ring shape according to the shape of the inner wall surface.

[Fifth Embodiment (Application Example of Light-Emitting Diode)] Next, an application example of the light-emitting diode according to the above-described embodiments will be specifically described.

FIG. 6 is a sectional view showing a storage type ashtray for an automobile or the like to which the light emitting diode of FIG. 1 is applied.

As shown in FIG. 6, the storage type ashtray of the present embodiment having a total of 40 is an open-close type ashtray installed in the console box 41 or the like of an automobile. The ashtray 40 is attached to the ashtray container 42 and the rear wall surface 41 of the console box or seat, and the ashtray container 4
2 and a container-like outer enclosure 43 that supports the 2 in a tiltable manner. In addition to these, a leaf spring or the like for holding the ashtray container 42 in a closed state and an open state is provided, but it is not shown here.

In such an ashtray 40, the light emitting diode 1 of the first embodiment shown in FIG.
It is attached to the upper wall surface of the. In the present embodiment, the light emitting diodes 1 are arranged in pairs on the left and right of the upper wall surface of the outer enclosure 43 (above and below the plane of FIG. 6).
It is provided individually and is operated by a car battery.

Therefore, according to the ashtray 40 of this embodiment,
Cigarette smoke containing nicotine and tar that fills the ashtray 40 after smoking can be decomposed by the photocatalytic reaction of the light emitting diode 1 (photocatalyst 7) and deodorizes the inside of the ashtray 40 that is a source of bad odor. Can be deodorized. Further, in this case, if the LED chip 2 of the light emitting diode 1 emits visible light having a color in addition to ultraviolet rays, for example, blue light, the visible light can illuminate the surroundings of the ashtray 40. The effect is that the ashtray 40 can be easily used at night.

As described above, the light emitting diode 1 of the first embodiment can be easily applied to the storage type ashtray 40 having a narrow space, and the air therein can be purified and deodorized. . This is exactly the same for the light emitting diodes 10 and 20 of the second embodiment and the third embodiment, and these can be used instead of the light emitting diode 1. In addition, these light emitting diodes 1,
The elements 10 and 20 can be similarly applied to a drawer-type storage type ashtray installed on a dashboard of an automobile. However, since this drawer type ashtray has a relatively large space, a plurality of L as in the fourth embodiment is used.
A light emitting diode 30 equipped with an ED chip 2 is suitable, and this can be installed, for example, on the wall surface above the storage recess of the ashtray container.

Since the storage type ashtray 40 is not often used, for example, the light emitting diode 1 is provided with a switch means and a timer means which are operated when the ashtray container 42 is opened in the power supply circuit. It is preferable that the operation is performed for a predetermined time only when necessary.

[Sixth Embodiment] Next, the light emitting diode of the above embodiment, in particular, the light emitting diode of the fourth embodiment provided with a plurality of LED chips is transformed into a special shape and formed as a coaster (cup receiver). The applied example will be described.

FIG. 7 is a sectional view showing the coaster.
In the figure, the same reference numerals are used for the same or corresponding parts as in the above-described embodiments.

As shown in FIG. 7, the coaster of this embodiment, which is designated by 50 in its entirety, is the same as the light emitting diode 30 (20) of the fourth embodiment of FIGS. 4 and 5 (or the third embodiment of FIG. 3). The outer surface of the cap 6 carrying the photocatalyst 7 is formed into a saucer shape, and the whole is transformed into a coaster shape. That is, the coaster 50 of the present embodiment has a coaster body 51 whose outer (upper) surface is formed in a saucer shape.
And L that mainly emits ultraviolet rays having a wavelength of 360 to 400 nm
The ED chip 2 and the stem 8 as a mounting substrate that fixedly supports the LED chip 2 are formed. The coaster body 51 is made of a transparent material such as glass, and is hermetically bonded to the stem 8. In addition, a photocatalyst consisting of a thin film of titanium dioxide 7
Are provided on almost the entire outer surface of the coaster body 51. It should be noted that this structure including the stem 8 can be replaced with the all-mold type shown in FIG. 1 or FIG.

Therefore, the coaster 50 of this embodiment including these elements is used in the first to fourth embodiments (in particular,
A light emitting diode basically the same as the light emitting diode of the fourth embodiment) is formed. In this embodiment, a base portion 52 is provided on the lower surface side of the coaster body 51 to protect the external leads of the LED chip 2 and to form a mounting surface for the surface of a table or the like. This base 52
Can be formed from an appropriately colored synthetic resin material or the like.

Further, in the coaster 50 of the present embodiment, a plurality of LED chips 2 are used, and they are appropriately dispersed and arranged on the stem 8. However, the number of the LED chips 2 may be one. These LED chips 2 are adapted to be operated by an appropriate DC power supply, for example, a half-wave rectified household AC power supply.

Therefore, according to the coaster 50 of this embodiment, since the photocatalyst 7 carried on the upper surface of the coaster body 51 is activated by the ultraviolet rays emitted from the LED chip 2, the activated photocatalyst 7 is The photocatalytic reaction forms an antibacterial surface having a bactericidal activity against the attached bacteria and the like. Therefore, the upper surface of the coaster body 51 on which the cup c or the like is placed can be always kept clean and hygienic. Further, in this case, by using the LED chip 2 that emits visible light having a color together with ultraviolet rays, it is possible to form the coaster 50 that emits the color, thereby enhancing the aesthetic effect and providing a clean impression. Can be given.

As described above, in the light emitting diodes of the first to fourth embodiments (especially, the fourth embodiment), the cap 6 can be formed in various shapes, and the coaster as in the present embodiment can be formed. It is also possible to form 50. Therefore, for example, in a structure such as the coaster 50 of the present embodiment, the coaster main body 51 can be formed in the shape of a drinking water container such as a pot, and the photocatalyst 7 can be carried on the inner surface thereof. It purifies drinking water,
Further, it is possible to obtain a drinking water container capable of producing delicious and healthy water.

Further, the light emitting diode of each of the above embodiments is
It is made of a pn-junction optical semiconductor crystal and has a wavelength of 360.
One or more LED chips that mainly radiate ultraviolet rays of up to 400 nm, a molded lens made of a transparent material that seals the LED chips, and a photocatalyst made of a thin film of titanium dioxide carried on the outer surface of the molded lens. It is equipped with. Since such a light emitting diode is formed as a small element and does not require a large space for installing it, it can be applied to any place including a narrow place. For example, in deodorizing applications, walls of automobiles or ordinary rooms, refrigerators, rockers, shoeboxes, toilets, closets, etc., as well as automobile ashtrays, clothes dryers and tableware dryers, air distribution in air conditioners. Examples include a route, a lid of a garbage container, a figurine or a decoration. In addition, in the application of purifying the water by contacting the light emitting diode with water, various drinking water pots, taps for water, bathtubs,
Examples include aquariums for ornamental fish. Furthermore, in the use for providing a sterilizing or antibacterial surface, a container for eating and drinking tools such as a chopstick stand, a sanitary container, a washbasin container such as a toothbrush stand, or a stationary storage part thereof, or a refrigerator shelf Places where many bacteria, such as, etc., adhere and are easily propagated (for example, the bottom of the container), telephones, scales, door handles, hanging leather, chair armrests, taps, etc. Alternatively, a toilet seat, a toilet bowl, or the like may be used. In these cases, the number of light emitting diodes as the photocatalytic element is the desired number or the desired number of Ls according to the specific application.
It can be used as a single light emitting diode including an ED chip.

Further, according to this light emitting diode, since a plurality of LED chips are provided, more ultraviolet rays are emitted, and more visible light having color is also emitted, so that the photocatalytic reaction ability of the photocatalyst is improved. Higher, and also
The emission capacity of colored visible light can be increased. Therefore, by the photocatalytic reaction of the photocatalyst, it is possible to purify air (deodorize), sterilize (antibacterial), prevent stains on the tar of the cigarette, purify water, and emit chromatic color. There is an effect that a high-performance light emitting diode can be obtained.

Although the photocatalyst 7 in each of the above-mentioned embodiments is composed of a thin film of titanium dioxide, other photocatalysts can be used when the present invention is carried out. Particularly, in the case of the photocatalyst 7 made of a thin film of titanium dioxide, it is made of a pn-junction optical semiconductor crystal and has a wavelength of 360 to 400.
The LED chip 2 that mainly emits ultraviolet rays of nm can be used, and near ultraviolet rays that are harmless to the human body can be used.

[0093]

As described above, the light emitting diode according to claim 1 is made of a pn-junction optical semiconductor crystal and mainly emits ultraviolet rays having a wavelength of 360 to 400 nm.
The above LED chip, a transparent lens that seals the LED chip, a cap made of a transparent glass material that is integrally coated on the outer surface of the lens, and a photocatalyst carried on the surface of the cap are provided. To do.

Therefore, according to this light emitting diode, the ultraviolet rays emitted from the LED chip pass through the transparent lens and further through the cap made of the transparent glass material that covers the transparent lens, and are carried on the surface thereof. It hits the photocatalyst and activates it. Since the activated photocatalyst forms an active surface having an oxidizing power, it oxidizes and decomposes an odor component in the air, a halogen compound in water, or an organic compound such as a tobacco tar, which comes into contact with the active surface. ,
It kills or inhibits the growth of microorganisms such as bacteria that come into contact with it. Therefore, it is possible to obtain a light-emitting diode capable of performing air purification (deodorization), sterilization (antibacterial), antifouling of cigarette tar, water purification, etc. by such a photocatalytic reaction of a photocatalyst, and The light emitting diode as the photocatalytic element has an effect that it can be used as a single light emitting diode including a desired number of LED chips or a desired number of LED chips according to its specific application.

The light emitting diode according to claim 2 has a pn
It is composed of bonded optical semiconductor crystals and has a wavelength of 360 to 4
It is provided with one or more LED chips that mainly emit 00 nm ultraviolet light, a lens made of a transparent material that seals the LED chips, and a photocatalyst carried on the outer surface of the lens.

Therefore, according to this light emitting diode, the ultraviolet rays radiated from the LED chip pass through the lens made of the transparent material and hit the photocatalyst carried on the surface thereof to activate it. Therefore, as in the case of claim 1, to obtain a light emitting diode capable of performing air purification (deodorization), sterilization (antibacterial), antifouling of cigarette tar, and water purification by photocatalytic reaction of photocatalyst. The light emitting diode as the photocatalytic element can be used as a single light emitting diode including a desired number of LED chips or a desired number of LED chips according to its specific application. .

A light emitting diode according to claim 3 is a pn
It is composed of bonded optical semiconductor crystals and has a wavelength of 360 to 4
One or more LED chips that mainly radiate ultraviolet rays of 00 nm, a stem that supports the LED chips, a cap that is hermetically fixed to the stem and is made of a transparent material that seals the LED chips, and the outside of the cap. And a photocatalyst carried on the surface.

Therefore, according to this light emitting diode, the ultraviolet rays emitted from the LED chip pass through the cap made of a transparent material and hit the photocatalyst carried on the outer surface thereof to activate it. Therefore, claim 1
In the same manner as in (1), it is possible to obtain a light-emitting diode capable of performing air purification (deodorization), sterilization (antibacterial), antifouling of cigarette tar, water purification, etc. by a photocatalytic reaction of a photocatalyst, and The light emitting diode as the photocatalyst element has an effect that it can be used as a single light emitting diode including a desired number of LED chips or a desired number of LED chips according to its specific application.

The light-emitting diode according to claim 4 is the light-emitting diode according to any one of claims 1 to 3, wherein the photocatalyst is a thin film of titanium dioxide. Therefore, the ultraviolet light emitted from the LED chip is It corresponds to a photocatalyst made into a thin film of titanium dioxide and efficiently activates it. Since such a light emitting diode is formed as a small element and does not require a large space for installing it, it can be applied to any place including a narrow place. For example, in applications where this light emitting diode is brought into contact with water to purify the water, various drinking water pots, taps for water, bathtubs,
Examples include aquariums for ornamental fish. Further, in the use for providing a sterilizing or antibacterial surface, a container for food and drink such as a chopstick stand, a sanitary container, a washbasin container such as a toothbrush stand, or a stationary storage part thereof, or a refrigerator shelf Places where many bacteria, such as, etc., adhere and are easily propagated (for example, the bottom of the container), telephones, scales, door handles, hanging leather, chair armrests, taps, etc. Alternatively, a toilet seat, a toilet bowl, or the like may be used.

According to a fifth aspect of the present invention, there is provided a light emitting diode according to any one of the first to fourth aspects, in addition to the LED thereof.
In addition to the effect of any one of claims 1 to 4, according to this light emitting diode, since the chip is mainly composed of one that mainly emits visible light having color and the ultraviolet light. Since visible light having a color of the emitted light emitted from the LED chip is not absorbed by the photocatalyst,
It is transparent as it is. Therefore, by the photocatalytic reaction of the photocatalyst, it is possible to purify air (deodorize), sterilize (antibacterial), prevent stains on tobacco tar, purify water, etc., and obtain a light emitting diode that emits light in that color. effective.

A light emitting diode according to claim 6 is the LED according to any one of claims 1 to 5.
The chip emits mainly blue light and the ultraviolet light pn
Since it is composed of a crystal body of a bonded gallium nitride (GaN) -based optical semiconductor, in addition to the effect of any one of claims 1 to 5, according to this light emitting diode, blue light is emitted. Since it is close to the wavelength of ultraviolet rays, L
The spectrum of the emitted light of the ED chip can be made relatively narrow in range, and higher luminous efficiency can be obtained. Therefore, the photocatalytic reaction of the photocatalyst can purify air (deodorize), sterilize (antibacterial), prevent stains on the tar of cigarettes, purify water, etc., and can also emit blue light, and the luminous efficiency is high. There is an effect that a good light emitting diode can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a light emitting diode according to a first embodiment of the present invention.

FIG. 2 is a sectional view schematically showing a light emitting diode according to a second embodiment of the present invention.

FIG. 3 is a sectional view schematically showing a light emitting diode according to a third embodiment of the present invention.

FIG. 4 is a plan view showing a light emitting diode according to a fourth embodiment of the present invention.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is a sectional view showing a storage type ashtray of an automobile or the like using the light emitting diode of FIG. 1 (or FIGS. 2 and 3).

FIG. 7 is a sectional view showing a coaster formed by modifying the light emitting diode of FIGS. 4 and 5.

[Explanation of symbols]

 1,10,20,30 Light emitting diode 2 LED chip 3 Molded lens 6 Cap 7 Photocatalyst (titanium dioxide thin film) 8 Stem

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location B01J 35/02 B01D 53/36 ZABH H01L 23/29 H01L 23/30 C 23/31

Claims (6)

[Claims] 1. A pn-junction optical semiconductor crystal body which mainly emits ultraviolet rays having a wavelength of 360 to 400 nm.
The LED chip described above, a transparent lens for sealing the LED chip, a cap made of a transparent glass material integrally coated on the outer surface of the lens, and a photocatalyst carried on the surface of the cap are provided. A light emitting diode characterized by being. 2. A pn-junction optical semiconductor crystal body which mainly emits ultraviolet rays having a wavelength of 360 to 400 nm.
A light emitting diode comprising the above LED chip, a lens made of a transparent material for sealing the LED chip, and a photocatalyst carried on the outer surface of the lens. 3. A pn-junction optical semiconductor crystal, which mainly emits ultraviolet rays having a wavelength of 360 to 400 nm.
The LED chip described above, a stem that supports the LED chip, a cap made of a transparent material that is hermetically fixed to the stem and seals the LED chip, and a photocatalyst carried on the outer surface of the cap. A light emitting diode characterized by comprising. 4. The light emitting diode according to claim 1, wherein the photocatalyst is a thin film of titanium dioxide. 5. The LED chip according to claim 1, wherein the LED chip mainly emits visible light having a color and ultraviolet rays having a wavelength of 360 to 400 nm. Light emitting diode. 6. The pn-junction gallium nitride (G) that mainly emits blue light and the ultraviolet light is used for the LED chip.
The light emitting diode according to claim 1, wherein the light emitting diode is made of a crystalline material of an aN) -based optical semiconductor.